An object such as this has become known from DE 10 2011 011 438 A1 filed by the same applicant. The disclosure content of this publication is to be incorporated into the disclosure content of the current invention in its entirety.
In the aforementioned publication, a clinch-rivet connection is produced on a metal component with the aid of an oscillating movement. The metal component is comprised of a pot-shaped lower part/workpiece that is connected to a plate-shaped upper part such that arced webs arranged around the periphery are molded onto the pot-shaped lower part, which engage in associated arc slots in the plate-shaped upper part, there to be reshaped in the sense of a widening applying the clinch-rivet method and using forming rollers. This results in a force-fit and form-fit abutment of the reshaped arc webs in the arc slots.
Accordingly, the non-deformed arc webs reaching through the arc slots of the lower part are brought into a cold flow state under the pressing force of forming rollers, and are thus expanded such that they rest in a force-fit and form-fit manner against the side walls of the arc slots in the plate-shaped upper part. In this way, the aforementioned clinch-rivet connection is produced.
However, the disadvantage of the known method is that a rotary oscillating movement has to be introduced onto the forming tool. The forming tool according to said publication is essentially a roller retainer, in which several forming rollers arranged around the periphery are present. The forming tool is rotatably driven by a driving tool carrying out an oscillating movement. With the known method, it is necessary that the pressing force onto the forming rollers needed for the deformation is also applied to the forming tool at the same time, thus using the forming tool for the production of the clinch-rivet connection by simultaneously applying an oscillating movement and a pressing force.
Another disadvantage of the known clinch-rivet method is that the adjustment of the oscillating movement is severely restricted because the oscillating movement is generated by means of a crank drive requiring a specific amplitude and a specific angle of rotation, which essentially cannot be changed.
The method for producing a clinch-rivet connection using a rotary oscillating movement for connecting two metal components is based on the subject matter of DE 10 2012 206 678 A1.
This publication already discloses a plug connector for connecting, in a rotationally engaged manner, a first component to a second component, in particular in a clutch unit, wherein the first component is provided with at least one connecting element configured as an arc web, which extends through a slot-shaped opening in the second component. The arc web of the first component extending through the slot of the second component is connected to the second component by way of a roll-forming method.
For this purpose, it is provided that the first and second component are arranged on a feed unit that is rotationally driven in an oscillating manner and at the same time is movable in an axial direction, which is able to firmly press the plugged-together components against cylindrical forming rollers fixedly arranged in a holder.
Accordingly, the cylindrical forming rollers roll in an oscillating manner clockwise and counter-clockwise across an angle range of, for example, 90 or 180 degrees relative to the circumferential direction of the rolling device so that each arc web is rolled over the rotatably mounted, cylindrical forming rollers several times, and a flow-pressing pressure is applied to the arc webs by the forming roller configured as a cylindrical roller so that piece by piece, the arc webs are pressed down and broadened, and thus a roll-formed connection between the first and the second component takes place.
The pressing down of the are webs can be in the range of a few mm. The feed of the cylindrical forming roller in Z-direction can be approximately 1/10 mm per rotation.
Accordingly, the cylindrical rollers are rolled many times over the respective arc web, for example, ten times or some hundred times, so that it broadens in a mushroom shape, and with its lateral surfaces rests on the edges delimiting the recess in the second component.
However, the disadvantage of such a roll-forming method is that after being rolled over multiple times, the edges on both sides of the arc webs settle, enlarged outwardly in a mushroom shape, on the upper side in the edge region of the recess of the second component, where they partially break or splinter. Thus, an uncontrolled deformation of the arc webs results, which poses the risk that due to the mushroom-shaped expansion of the arc webs beyond the edges of the recess in the second component, invisible fracture lines and undesired crystalline deformations in the structure of the arc webs are formed, which impair the stability of the roll-forming connection.
Thus, a roll-formed connection such as this can also not be examined for a crack-free quality by way of an x-ray or ultrasound examination.
Accordingly, the arc webs are steamrolled, so-to-speak. The price to be paid is the disadvantage of fracture lines in the area of the roller-formed cross sections of the web arcs.